Adopt while living in parents house

Hi there, I'm about to return from living overseas and plan to apply adopt from foster care. My parents have a good sized house with two levels and my seven year old and I will be living on the bottom floor. It has access to upstairs, where my parents live, but is like its own apartment with four bedrooms, a lounge, kitchen, two bathrooms, etc. My question is whether I'd get approved to foster in this situation or if I'd need to go and rent my own house. Then my next question is whether my parents could also get approved as foster carers so they could be respite carers, if needed, while we wait for the adoption process to be finalized. Many thanks!